Comparison of graphene oxide and graphitic carbon nitride filled carbon-phenolic composites: Thermomechanical properties and role of the strong electronegativity of nanofillers

Biogenic Synthesis of Graphitic Carbon Nitride for Photocatalytic Degradation of Organic Dyes

A simple approach of template growth of graphitic-carbon nitride (g-CN), a polymeric unit consisting of C, N, O, and H elements derived from extracts of green plant Aloe vera, which are rich in several chemical constituents, has been successfully experimented in this work. Comparing several other methods used for synthesizing g-CN involving a large amount of toxic components, here, we propose the simplest route economically and environmentally highly viable for near future. Green plants are highly rich in natural carbon and nitrogen compounds, such as acemannan, glucose, aloin, protein, etc. Way before g-CN research, many carbon-based materials have been synthesized for multifunctional properties, but g-CN has much benefit over them due to the presence of elements such as C, N, O, and H, thus making it electron-rich. Multifunctional properties of graphitic-carbon nitride interface bonding as a supercapacitor or as a metal-free catalyst thus help degrade dyes. Violet-blue broad band emission was even noticed when excited at 240 nm via C-C bonding (π-π* transition) in the absorption band with an extinction coefficient of ∼10⁴ M^-1 cm^-1. With our research, we want to pave new ways of synthesizing such materials present in our nature in a biological form, which can protect our environment, thus causing less harm to mankind.

Restricting Molecular Mobility in Polymer Nanocomposites with Self-Assembling Low-Molecular-Weight Gel Additives

Multiscale investigation of molecular gel additives in polymer matrices guides understanding of how solution-state assemblies result in mechanically enhanced, solid-state nanocomposites. Model polymers, poly(ethylene oxide- co-epichlorohydrin) (EO-EPI) and poly(vinyl acetate) (PVAc), were utilized as matrices and reinforced by cholesterol-pyridine (CP) nanofiber networks. The CP nanofillers suppress ethylene oxide segment melting for EO-EPI composites, whereas for PVAc nanocomposites, cause a polymer-gel dissociation transition. Incorporation of crystalline CP fiber networks led to an order of magnitude increase in tensile storage modulus due to restrictions on polymer chain mobility. This decrease in molecular mobility was confirmed by decreased loss moduli for both EO-EPI and PVAc composites. Excitingly, PVAc nanocomposites display an additional relaxation mode caused by release of PVAc chains from the transient molecular gel assembly. For both EO-EPI and PVAc composites, bulk flow can be suppressed to temperatures up to 100 °C by simply increasing the CP concentration.